1. Field of the Invention
The invention relates to an apparatus and method for pivotal fastening of an active surface. The active surface may, in particular, be arranged on a spoiler. The apparatus may be mounted to a wind tunnel model of an aircraft, and can comprise a bearing block and a strip pivotally mounted on a shaft, wherein the strip is connected to the active surface.
2. Discussion of Background Information
Every new type of aircraft requires complex and comprehensive aerodynamic tests and measurements in the wind tunnel. To this end, realistic, true-to-scale models are produced, which are introduced into the wind tunnel by a model suspension. The aircraft models are generally equipped, at least in part, with the same aerodynamic active surfaces as the original to be simulated. Thus, a complex wind tunnel model of an aircraft can be equipped, for example, with ailerons, elevators, a rudder, landing flaps, and high-lift systems. In addition, spoilers, winglets, or engine simulators may be provided to increase the reality of the simulation in the wind tunnel.
All aerodynamic and/or active surfaces have in common that they must be tested in a plurality of angular positions in the wind tunnel to do justice to all the situations arising in everyday flying operation.
In the known embodiments of wind tunnel models, for example, spoilers are attached to the wind tunnel model with a fixed angular position in each case, with the result that in particular a high time expenditure for retrofitting the aircraft model is obtained when conducting comprehensive series of measurements with plurality of aerodynamic surfaces set at different angles in each case. The retrofitting expenditure is of marked importance given the high wind tunnel utilization costs. In addition, it is necessary in this case to hold in readiness a large number of spoilers with different angular positions in each case, resulting in a higher production and storage expenditure.
Alternatively, it is possible to dispose a spoiler pivotally on a shaft and firmly clamp the spoiler on the shaft with a screw connection when a defined angular position is reached. However, this holder has the disadvantage of a relatively high imprecision. In addition, an uncontrolled angular adjustment of the spoiler, and measurement errors thereby induced in the wind tunnel are possible due to the large lever effect of the active surface on the shaft.
DE 295 01 392 U1 discloses an adjustable shaft component in which a vertical tube is fixed with one end pivotally on the end of a horizontal tube, wherein two locking blocks of the shaft component are pressed firmly against one another with a screw connection for fixing the instantaneous pivoting position of the vertical tube. DE 102 08 258 B4 describes an apparatus for providing a variable flow profile. A drive of a linear thrust element is known from DE 103 52 130 A1.